He's enormous, and men his size tend to count on the fact that they hit hard in a fight. She anticipates his next move as soon as he jumps out of the way of her foot, and she's quick to launch herself to the side, rebound off of the perpendicular wall, and come back with a punch aimed squarely at his jaw.

She has a few people she can train with, who are willing to spar, but even those who will come to blows with her aren't really willing to hurt her. He doesn't know her. He has no reason to not want to draw blood. She's gotten a certain amount of satisfaction fighting against the monsters beyond the perimeter, but she was trained for this, and it's been a while.

Funnily enough, in a way, she was trained for exactly this. Not just the face to face violence with another human being, but being in an incredibly tight space with an attacker far larger than her, turning everything in the space, including the confines of the space itself, into an advantage.

Always four steps ahead. That's the only way to keep from getting flattened, and fighting monsters hardly requires so much forethought. This is better. If her punch connects, she'll follow with an uppercut. If he blocks her, he'll give her additional momentum, and she'll use it to duck around him. If he's actually quick enough to grab her, well, that's a whole new approach, isn't it?